Tao Ai

MICROWAVE ABSORBING CHARACTERISTICS OF ASPHALT MIXES WITH CARBONYL IRON POWDER

Power microwave was adopted to heat asphalt mixes with carbonyl iron powder (CIP) by its microwave absorbing characteristics. The Arch re∞ectivity system was employed for re∞ectivity tests in the frequency range of 2:0 » 4:0GHz, and road properties of the asphalt mixes with difierent heating techniques were studied. The results indicate that 30mm thickness of the asphalt mixes with the ratio of CIP absorber to asphalt 0.1 : 1.5, can efiectively absorb microwave with a i19:1dB absorbing peak at 2.45GHz frequency. Microwave heating rate for asphalt mixes with CIP is 16 times higher than that for ordinary asphalt mixes. Microwave heating can enhance road properties of the asphalt mixes, such as Marshall stability, ∞ow value, dynamic stability and splitting strength at low temperature to a certain extant when the ratio of CIP absorber to asphalt is from 0.1 : 1.5 to 0.3 : 1.5.

Laboratory Preparation and Microwave Heating Test of CIPs/Asphalt Binder

Microwave heating technology has been adopted in asphalt pavement maintenance to reduce the total cost resulting from the energy consumption. In this paper, laboratory preparation and microwave heating tests of carbonyl iron powders (CIPs)/asphalt binder were carried out. The modeling procedure, microwave heating efficiency and the properties of the CIPs/asphalt binder - such as penetration, softening point and ductility - were studied. The results show that microwave heating efficiency of CIPs/asphalt binder is enormously higher than that of ordinary asphalt binder. Adding a certain amount of CIPs can improve the asphalt binders resistance to deformation at high temperature. All of these can put forward a theoretical basis to design asphalt mixtures suitable for use in snow and ice removal by microwave pavement maintenance vehicles.